Improvement in cables and testing-posts for subterranean telegraphs



S. F. VAN GEOATE; CABLE AND TESTING POST FOR SUBTERRANEAN TBLBGRAPHS.

PatentedNov. 9, 1869.

UNITED STATES PATENT OFFICE.

S. F. VAN CHOATE, 'OF BOSTON. MASSACHUSETTS.

IMPROVEMENT lN CABLES AND ESTING-POSTS FOR SUBTERRANl-IAN TELEGRAPHS.

Spcciiicalion forming part of Letters Patent No. 96,641, dated November9, 1869.

Too whom it may concern:

Be it known that I, SILVANUS FREDERICK VAN CHOATE, of Boston, in thecounty of Suffolk and State of Massachusetts, have invented Improvementsin Telegraphy; and I do hereby declare that the following, taken inconnection with the drawings which accompany and form part of thisspecification, is a:description of my invention sufiicient to enablethose skilled in the art to practice it.

My inventionrelates to the manufacture and use for telegraphic purposesof conductors con structed in a peculiar manner, and also'to operatingand testing the same, as hereinafter to be described.

stance or material, and otherwise protect said fiber and its inclosedconductor as may seem proper.

The objects intended by interposing a coating of clean fiber between theconducting-wire and the insulating or protecting material may be brieflystated.

The electrical current, which 18 found to be more or less retarded incase the conductor is covered directly by gutta-percha,asphaltum,

or other gummy, bituminous, or greasy substance, is, by theinterposition of the clean fibrous cushion, saved from such retardation.The open nature of the cushion thus surrounding the conductor allows acirculation of air around the conductor through the ends of the cable,while the cable, if strained or attenuated by restingupon prominences onthe oceanbed, or by being caught in the process of paying out, SHHGI'SDOessential injury, as its conductor, lying loosely in its cushionedenvelope, is drawn through the. covering without suffering the strainwhich it would be subjected to were the wire a rigid and homogeneouspart of the entire structure.

Cables constructed in this manner may be laid under the ground in thefollowing manner:

Wooden scantlings or strips of plank of desired dimensionssay two byfour inches and of any length-are prepared with grooves to correspondwith the dimensions of the cable. This wood is thoroughly prepared withasphalt varnish or-other preservative substance, in-order to preventdecay. A proper ditch being dug, the lower strip or scantling is laiddown at the bottom of the ditch with the groove upward. The cable isthen placed along in the groove, and the top scant'ling or strip isplaced in position over thefirst strip and spiked or otherwise secured,after which the .ditch is filled up.

' These strips may be laid in a continuous series.

The cable may also be protected by a kind of metal piping formed of afillet or strip of sheet lead or other metal and wound by machineryaround the cable in aspiral or other manner.

After mycable is laid underground, I provide for regulating and testingit as follows:

Testing boxes or posts (shown in the drawing) are located at desirablepoints along the line of telegraph-say a mile or two miles apart. Fordurability they may be made of cast-iron. These boxes have a door, whichis secured by a lock and key, and so constructed as to exclude the rain.They are set upright, similar to a post, and are hollow, closed at thetop and open at the bottom, which is connected with the scantlingcontaining the cable, and, if necessary to give them permanency, theymay be secured to a post, as represented in the drawing, the post beingset firmly in the ground by the sideof the scantling, which latter maybe secured to the post by spikes or otherwise.

Holes are formed in the top strip or scantling, under the bottom end of,the box, so as to allow the ends of the cables to pass up through thehollow post to reach the testing-box, which is located in the post.

- In order to prevent the moisture from comspace is to keep the interiorof the inner box dry if by any means moisture should get inside of thepost-box. The inside box is provided with a door, to be opened when itis desired to get at the connections of the wires inside. In this innerboxl arrange as many metallic-screw-cnps or binding screw-posts as maybe necessary to connect the wires in the cables. These screw-posts arefastened to strips arranged to separate them, and are so constructed asto have'an air-space behind them, as seen in the drawing. A ground-wireis also arranged or connected with the postbox, or, the box being metal,it may answer as a ground itself. This ground or ground-wire is used toterminate the wires of the cables at this point when desired for testingthe circuits, forming a circuit from the testing-box to. the next box,or to the next oifice or station, as may be desired.

To facilitate testing the cables or one of the wires of the cables, andto direct operators in so doing, the post-boxes, as well as thescrewconnections, are numbered, as maybe desired, the latter tocorrespond to the wires in-the cables and the posts to correspond with.lists kept at the stations or offices.

Suppose it necessary or desirable to have tested the wire correspondingto No; 1, to the right, which might be north, and also at postbox No. l.A repair-man would besent out, and on arriving at the post-box No. 1 hewould proceed to unlock and open the outside door of the post-box andlikewise theinside box. He

would unscrew or disconnect the .wires at' screw-cup No. 1, and take theend of thewire' to the right, and would connect it toa pocket orportable instrument or sounder, which he could place on the top of thepost-box. He would then connect the ground to his instrument, so as toform a circuit to the right through the magnet of his instrument, whenhe could, in case the circuit was complete, communicate to thenextpost-box or to any office in the circuit to the right he desired,provided therewas a battery in the circuit. But if the wire No. lwasbroken between this point (No. 1) and the battery, then he could notcommu nicate, and thus any of the wires in the testing-box either to theright or left could be tested and any difiieulty between the offices andboxes detected. In order to do this it is absolutely necessary to havethis ground or ground-wire at this point, because without it a singlewire could not be tested without disturbing another wire for the purposeof form-.

. ing a circuit.

Other tests of any wire-sayNo. 1may be performed withoutthe employmentof a ground or ground-wire located at the testing-post, by taking one ofthe other wiressayNo. 2and forming a, circuit back to the battery, or byconnecting the testing-instrument between the two ends of any of thewires in the box; but the ground-wire or ground-connection at the postor testing-point is the only plan to test a wirewithoutdisturbinganotherwire. Besides it may be very important to be operating on No. lto theleft while the testing is going on to the right, in which case the wireto the left may be connected to the ground, when a circuit could beoperated to the left undisturbed while the difficulty existed to theright.

In conctructing lines of land-telegraph, to save the trouble anddifficulty of splicing and for other reasons, including economy, I makemy cables in lengths only suliicient to reach from one testing-box toanother. This is very important, as it saves the necessity of providingat each section of the cable the various materials and compositions usedin its covering and insulation.- In cases where a cable containsadozen'or two of wires their splicing, insulating, and wrapping would bea tedious and expensive operation, and somewhat uncertain in itsresults.

The testing-post, as well as the inner box, together with all itsattachments excepting the binding-screws, are prepared to preventmoisture and decay and the whole thoroughly coated inside and out withasphalt varnish,-

to protect the iron from rusting and to prevent spiders or other insectsfrom making .webs or inhabiting the inside cavities.

In cases where cables are laid across rivers or other waters, atesting-post is located on either side.

, The drawings show, in Figure 1, an elevation of an apparatus embodyingmy invention.

the elevation being taken with the door of the box-post open and withthe door of the inner boxopen, showingthe terminal-adjacent ends of twosections of cable as separated into its contained wire-conductors, the.corresponding wires of each section being shown as applied to thescrew-cups or couplings. Fig. 2 is a sectional plan, the section beingtaken in the plane of the line z z in Fig. 1,the doors of the apparatus,however, being shown as closed in Fig. 2. Fig. 3 represents a cablecomposed of, three conductingwires, each covered or. wrapped with afibrous material,-in accordance with my invention, before being coveredwith asphalt varnish, gutta-pereha, or other suitable non-conductingrepellent of moisture.

The iron box-post is marked a, the interior wooden box b,the woodenstrips across theinterior of and at the back of box b are denoted bye,and the screw-cups or couplings on said strips .are marked d, eachbeingalso marked with the number denoting a special wire of the cable.The scantling or horizontal wooden troughlike strips are marked, thelower one e and the upper onef, and the wooden post to which a isconfined is marked 9.

7:, denotes the entire cable or collection of wires and their and itswrappings and envel- Sections or end views of the horizontal tube orscantling are shown at the details A, B, and G. I

The separate naked wireconductors which are made up into a cable aremarked 1, 2, &c. The fibrous wrapping or plaiting on each wire is marked5, and thenon-conducting waterproof covering of each wire is marked 70.

The separate wires may befurther prepared by other layers or coatings ofany desired ma.- terial, and when sufficiently coated or protected theseparately protected or covered wire-conductors are twisted together anydesired amount, and the assemblage of wires 'thus twisted may be coveredand wrapped terranean telegraph. cables have been submerged withinscantling boxes or troughs, and, further, that testing-boxes in someform have been adopted. So far as my knowledge (which has been veryextensive) extends,however, no provision has been made heretofore for aperfect protection against ingress of moisture to theinterior of theseboxes and to the cable, and the failure to provide this has been to agreat extent the cause of the failure in the successful working of theabove-mentioned class of telegraph-lines. Neither have the termini ofthe wires within the testingboxes been provided with individualdistinguishing-characters .to enable an accident to be instantlydetected.

By my construction of the testing-boxes I secure perfect protection ofthe contents of the inner box from moisture, &c., while by my system ofnumbering the screw-caps-or connections I am enabled to designate to therepair-man the exact wire which is disabled.

The numerical arrangement of the test-boxes themselves greatlyfacilitates the repairing of the cable, inasmuch as the time of therepair is economized as well as that required for discovering thelocality of the injury to the wire.

I claim 1. A conducting-cable for telegraphic purposes, in which a layerof clean, dry, fibrous material is interposed between the conductingwireandthe insulating-coating, in the manner and for the purposes set forth.

2. The construction of the testing-boxes for telegraph purposes, wherebyaccess of moisture is prevented, substantially as hereinbeforedescribed.

3. In the construction of testing-boxes of telegraph-wires, affixiugsuitable characters for designating individual wires as well as theboxes themselves, substantially as before described.

4. The combination, with telegraph-condoctors, of ground-wires locatedat the testboxes of the same, substantially as and for the purposesspecified.

5. The combination,with subterranean telegraphic conductors andtest-boxes, of ground wires, substantially as and for the purposesspecified.

S. F. VAN OHOATE. \Vitnesses:

J. B. CROSBY, F. GOULD.-

